peak hours

[epsgunner]

I hear you..

My HF meter AMP Section died after 1 use.. climbs up by itself.. even after trying to reset with touching the leads..

Latest numbers.. 14.4V 6.7A 95W PWM 99%..



New Numbers.. 14.4V 7.0A 101W PWM 99%..

[miike012]

Try using PV Watts http://mapserve3.nrel.gov/PVWatts_Viewer/index.html

We all know this program.

Ok I went to the website you posted and the questions that I have are.. "PV System Specifications" I dont know what to put under DC Rating, DC to AC Derate factor, and how do I determine the angle for the array tilt and array azimuth entries?

The product I am thinking of purchasing is http://us.sunpowercorp.com/homes/pro...ar-panels/e20/

[epsgunner]

For DC Rating (where it has 4.0) change to be your total PANEL SETUP..

Example. I have 5 panels at 145 watts.. = 725..

Since the field is KW.. it would be: .725

What size panel(s) are you getting?? that page doens't say size..

Found 327W rating on the PDF.. how many panels?? 1, 2, 5,???

For the proper TILT angle we would need you latitude or zip code.. (got it 33.38)

Then 33.38 * .76 + 3.1 = angle.. 28.48

The Azimuth is usually DIRECTLY SOUTH (aka 180 is correct for most) unless you can't mount your panels facing directly south..

[Sunking]

I'm unsure then I guess.

I have the Morningstar TS-45 PWM, and not the MPPT version..

That explains the low efficiency.

[epsgunner]

That explains the low efficiency.

True I guess.. but the extra 300 clam$ in my pocket makes me feel better..

Glad I went with 5 panels.. though by next spring and a JOB I may double the number and go 24v..

I'll be in south TX with lots of pure sun going on.. so the 725 watts (rated) isn't a bad start..

I can't get a good test here in NJ this week as we've got rain forcast everyday..

Do you think a GOOD battery would give me possibly more accurate numbers??

The battery I am using (car battery) has a BLACKEND positive terminal.. so I'm pretty sure its shot..

Usually by the next day (of testing) its back to 12.1V from the 13.9 or higher I leave it at..

ETA:

Just using the MS String Calc..

The irony is the MS TS45 MPPT is rated for a max of 600 Watts at 12v.. so the max would be 4 panels and 580 watts.. going PWM makes it 5 panels listed and 40.X amps..

I could squeeze one more panel and be at 48amps.. the PWM version has a overlimit upto 50 amps..

I'd have to get the TS60 MPPT to run my 5th panel..

[Naptown]

Ok I went to the website you posted and the questions that I have are.. "PV System Specifications" I dont know what to put under DC Rating, DC to AC Derate factor, and how do I determine the angle for the array tilt and array azimuth entries?

The product I am thinking of purchasing is http://us.sunpowercorp.com/homes/pro...ar-panels/e20/

Standard derate on that program is 77%
You can tweak it depending on how you design the system.
Anyway top number is what the power tolerance on the module is Generally a +/- number if the manufacturer says it is -3-=5% use the -3 or enter .97 if -0 +3% use 1
If your inverter is rated for efficiency use that number.
If you are using microinverters set module mismatch to the highest allowable number
DC and AC losses unless you want to calculate voltage drop for each segment leave alone except if you are using microinverters then set DC to highest allowable figure.
Leave other items as default.

[miike012]

I am looking for information on temperature coef. for Power. In my report I would like to talk about how it is calculated, and why buying a system with a low coef. will be most beneficial ( I need to back this with data) in hot climates..I live in arizona.

Can anyone guide me to any reading materials? I have been searching on google but no luck


Is this a good website to start off with

http://photovoltaics.sandia.gov/docs/PDF/IEDFB5~1.pdf

[websterize]

I learned a lot about temperature coefficients from this "PV Math" piece by John Wiles:

http://www.nmsu.edu/~tdi/Photovoltaics/Codes-Stds/PV%20MATH.pdf

[miike012]

Are my calculations correct? I want to calculate max energy of a single cell in one day.

Assuming there is 6 haours of peak sun ( I live in Arizona)

1. p(1000 w/m^2)*(20%) = 200w/m^2

I chose the value 1000 w/m^2 because this is the most power any panel can intake and I multiplies it by 20% because that is the efficiency of my panel.

From line 1. 200w/m^2*6 hours = 1.2 kwh in a day.

Is this correct?

[russ]

1) If your panel is 1m2 and all else is at 'normal'

2) For temp coefficient try this link http://homepower.com/files/PVModuleB...pecDetails.pdf

[miike012]

[QUOTE=russ;48132]1) If your panel is 1m2 and all else is at 'normal'

what do you mean by normal? and does 1m2 mean 1 meter^2?

[russ]

Comments within the text

[QUOTE=miike012;48133]

1) If your panel is 1m2 and all else is at 'normal'

what do you mean by normal? temperature, humidity, air clarity for a start

and does 1m2 mean 1 meter^2? What else might it possibly mean - one never uses the ^ sign that I have seen

[inetdog]

"and does 1m2 mean 1 meter^2? What else might it possibly mean - one never uses the ^ sign that I have seen"

The use of "^" for exponentiation when you can't do superscripts is pretty common among science and particularly computer science types. I don't see it in specs or used by engineers much. The other common usage among that group would be meter**2.

[miike012]

is is 1.72 kwh/(m^2-day) energy produced good, bad, or average?

[miike012]

Does anyone know the rate at which srp raises the dollar amount per kwh? I can't find this info online...